Device and methods for the acquisition and automatic processing of data obtained from optical codes

ABSTRACT

The device for the acquisition and automatic processing of data obtained from optical codes comprises a CMOS optical sensor; an analog processing unit connected to the optical sensor; an analog/digital conversion unit connected to the analog processing unit; a logic control unit connected to the CMOS optical sensor, the analog processing unit and the analog/digital conversion unit; and a data-processing unit connected to the logic control unit and the analog/digital conversion unit. The CMOS optical sensor and at least one of the analog processing, analog/digital conversion, logic control and data processing units are integrated in. a single chip. The data processing unit processes the digital signals corresponding to the image acquired by the CMOS sensor and e the optically coded data.

[0001] This application is a continuation of application Ser. No.10/247,681 filed Sep. 20, 2002 and 09/432,105, filed Nov. 2, 1998. Theentire contents of both applications are hereby incorporated herein byreference.

[0002] The present invention relates to a device and a method for theacquisition and automatic processing of data obtained from opticalcodes.

[0003] Hereinafter, the term “optical code” indicates any graphicrepresentation which has the function of storing coded data. A specificexample of an optical code comprises linear or two-dimensional codes,wherein data is coded by appropriate combinations of elements with apredetermined shape, i.e. square, rectangles or hexagons, of dark colors(normally black), separated by light elements (spaces, normally white),such as bar codes, stacked codes (including PDF417), Maxicodes,Datamatrix, QR codes, or color codes etc. More generally, the term“optical code” further comprises other graphic forms with a data-codingfunction, including uncoded printed characters (letters, numbers etc.)and specific shapes (patterns) (such as stamps, logos, signatures etc).

[0004] In order to acquire optical data, optical sensors are required,converting the data coding image into electric signals, correlated tothe brightness of the image dots, which can be automatically processedand decoded (through electronic processors).

BACKGROUND OF THE INVENTION

[0005] At present, optical sensors are manufactured using CCD 30 (ChargeCoupled Device) technology. However, these sensors have disadvantagescaused by a not always satisfactory reading performance, complexity,cost and size of the entire reading device.

[0006] Furthermore, for the manufacture of optical sensors it hasalready been proposed to use the CMOS technology, presently employedonly in integrated electronic circuits. Hitherto. however, CCDtechnology has been preferred to CMOS technology, since its performanceis better as to quantic efficiency, optical “fill factor” (i.e. thefraction of the useful area occupied by the individual detection elementor pixel in order to acquire optical data), dark current leakage,reading noise and dynamics.

[0007] Recently, active pixel CMOS sensors (with an amplificationsection inside the pixel) have been developed, which have performancelevels competitive with CCD sensors, but far greater functionalcapabilities. An image acquisition device can be divided into two parts,i.e. a (linear or matrix-type) optical sensor, supplying output electricsignals correlated to the received light, and a unit for processing theelectric signals. With the CCD technology used hitherto, whenever theprocessing unit has to collect data from the optical sensor it mustaccess all the pixels forming the optical sensor in a predeterminedsequence. On the other hand, CMOS technology allows the processing unitto access any pixel directly, without having to comply with a specificorder, and without the need to access all the existing pixels. Inaddition, CMOS sensors are fully compatible with logic circuits producedusing CMOS technology itself.

SUMMARY OF THE INVENTION

[0008] The object of the invention is thus to provide a device and amethod for acquiring optical data, exploiting the intrinsic advantagesof CMOS technology, compared with CCD technology.

[0009] According to the present invention, a device is provided for theacquisition and automatic processing of data from optical codes,characterized, in combination, by:

[0010] a CMOS optical sensor;

[0011] an analog processing unit connected to said CMOS optical sensor;

[0012] an analog/digital conversion unit connected to said analogprocessing unit; and

[0013] a data-processing unit, connected to said analog/digitalconversion unit

[0014] The CMOS sensor can be of linear or matrix type; the device isalso provided with a display unit and a keyboard and/or a mouse. Aninterface permits connection to radio, telephone, GSM or satellitesystems.

[0015] The CMOS sensor and at least one of the analog and digital imageprocessing units, are preferably integrated in a single chip;consequently the device is cheap, fast and less sensitive to noise.

[0016] The device initially advantageously acquires low-resolutionimages; in the low-resolution images, it looks for interest regions;then it acquires high-resolution images in the interest regions anddecodes data in the high-resolution images.

[0017] According to the invention, a method is also provided forautomatically acquiring data obtained from optical codes, comprising thesteps of generating an analog electric signal correlated to thebrightness of an image through a CMOS optical sensor; processing saidanalog electric signal in an analog manner; converting said analogelectric signal to a digital signal; and processing said digital signalto extract coded optical data.

[0018] In addition, the invention relates to a device for automaticacquisition of data obtained from optical codes, characterized, incombination, by:

[0019] a CMOS optical sensor;

[0020] an analog processing unit connected to said CMOS optical sensor;and

[0021] an analog/digital conversion unit connected to said analogprocessing unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further characteristics of the invention will become apparentfrom the description of some preferred embodiments, provided purely byway of no example and illustrated in the attached drawings, wherein:

[0023]FIG. 1. shows a block diagram of a device for the 10 acquisitionand automatic processing of data according to a first embodiment of theinvention;

[0024]FIG. 2 shows a block diagram of the device according to a secondembodiment of the invention;

[0025]FIG. 3 shows a block diagram of the device according to a thirdembodiment of the invention;

[0026]FIG. 4 shows a block diagram of the device according to a fourthembodiment of the invention;

[0027]FIG. 5 shows a block diagram of the device according to a fifthembodiment of the invention;

[0028]FIG. 6 shows a block diagram of the device according to a sixthembodiment of the invention;

[0029]FIG. 7 shows a block diagram of the device according to a seventhembodiment of the invention;

[0030]FIG. 8 shows a more detailed block diagram of the device of FIG.1, according to a first variant;

[0031]FIG. 9 shows a more detailed block diagram of the device of FIG.1, according to a second, variant;

[0032]FIG. 10 shows a more detailed block diagram of the device of FIG.1, according to a third variant;

[0033]FIG. 11 illustrates a flowchart of a method for the acquisitionand automatic processing of data according to the  invention;

[0034]FIGS. 12a and 12 b show two portions of a sensor used in thepresent device;

[0035]FIGS. 13a, 13 b and 13 c show optical codes superimposed on a gridrepresenting a first shape of the pixels of the image acquisitionsystem;

[0036]FIGS. 14a, 14 b and 14 c show optical codes superimposed on a gridrepresenting a second shape of the pixels of the image acquisitionsystem; and

[0037]FIG. 15 illustrates a flowchart of a variant of the method forautomatic data acquisition according to the invention.

DETAILED DESCRIPTION OP THE INVENTION

[0038] In FIG. 1, a device 1 for acquisition and automatic processing ofdata comprises an image detector 2 and a processing unit 3. In turn, theimage detector 2 comprises, in cascade with one another, a CMOS sensor5, an analog processing unit 6 and an A/D converter 7.

[0039] In detail, the CMOS sensor 5, of known type, comprises a linearor matrix-type array of sensing elements produced using CMOS technologyand intended to provide each an image element (pixel). Hereinafter, forthe sake of simplicity of description, the term pixel indicates both theimage elements taken from each sensing element and the sensing elementsthemselves. The CMOS sensor 5 then supplies at the output an analogsignal correlated to the quantity of light incident on the sensingelements themselves.

[0040] The analog processing unit 6, receiving the output signal fromCMOS sensor 5 on a line 8, has the function of adapting the outputsignal from CMOS sensor 5 and allowing subsequent digital conversion ofthe signal; in particular, it serves the purpose of making the signalcompatible with 30 .the voltage values required by the A/D converter 7,through automatic gain control; eliminating the (thermal arid electromagnetic) noise generated inside CMOS sensor 5, or picked up from theexterior; and modifying the signal to compensate blurring or excessiveimage definition.

[0041] A/D converter 7, connected to the output of the analog processingunit 6 via a line 9, transforms the analog signal supplied by the analogprocessing unit 6 into a succession of digital pulses, by sampling theanalog signal at suitable moments and coding the data in digital form.In particular, 5 in the simplest case, A/D converter 7 can also use asingle bit (and supply only a white/black data), but more generally itis a N bit converter (e.g. 4, 6, 8, 10, 12, 16).

[0042] A digital logic control unit 10 is connected to CMOS 10 sensor 5,to analog processing unit 6 and to A/D converter 7, through respectivelines 11-13, and supplies them with control signals necessary for theiroperation, for example activation and synchronism signals. Logic controlunit 10 comprises hardware and software components for managing blocks5-7 and can also carry out very complex tasks.

[0043] The output 7 a of A/D converter 7 is connected to amicroprocessor 15, belonging to the processing unit 3 and connected toan own ROM memory 16 for program storing, and to an own RAM memory 17for storing data, digital image and program information duringexecution. Microprocessor 15 is connected to logic control unit 10 via aline 18 and supplies control signals for acquiring the signalsassociated with all the pixels (frame), or acquiring the signalsassociated only with some specific pixels, as described hereinafter ingreater detail with reference to FIG. 11. Depending on the application,microprocessor 15 can also control pixel acquisition in non-consecutiveorder. In addition, it processes the digital image data, extracts thecoded data 30 from the acquired image and optionally processes this dataaccording to known algorithms.

[0044] In the device 1, CMOS sensor 5 and at least one of the elementsof the image detector 2 and/or the processing unit 3, are integrated ina single chip. In the example illustrated in FIG. 1, for example theentire device 1, including the image detector 2 and the processing unit3, is integrated in a single chip 20.

[0045] The device 1 is thus very compact and has lower 5 productioncosts and a high image processing speed, due to the closeness of thecomponents and lack of external connections.

[0046]FIG. 2 shows a device 1 including, in addition to the blocks shownin FIG. 1, a battery supply unit 80, connected to the image detector 2and to the processing unit 3, for supplying power to device 1, and twouser interfaces, specifically an input interface 21 and an outputinterface 22, also supplied by the battery supply unit 80, in a mannernot shown. The input interface 21 is connected to an input device 81,for example a keyboard or a mouse, for inputting data and commands; theoutput interface 22 is connected to an output device 82, typically adisplay unit, to display a text and/or images. The input interface 21and output interface 22 are connected to the microprocessor 15 via adata and control bus 23.

[0047] The device 1 of FIG. 2 is also provided with a data transfer and.control interface 35, for remote transmission and receipt to/from otherdevices or to/from a central unit (not shown); typically this interfacepermits dispatch of data extracted from the image acquired bymicroprocessor 15.

[0048] In this case also, the CMOS sensor 5 can be of the 30·linear ormatrix type.

[0049]FIG. 3 shows an embodiment wherein, instead of being concentratedin an appropriate unit—(logic control unit 10), the logic control unitis distributed within blocks forming CMOS sensor 5, analog processingunit 6 and A/D converter 7. The logic control unit 10 is thus eliminatedand microprocessor 15 is interfaced directly with blocks 5, 6 and 7.

[0050] According to a variant, also shown in the block diagram 5 of FIG.3, the logic control unit is provided inside the microprocessor 15.Therefore, also here, microprocessor 15 is interfaced directly withblocks 5, 6 and 7. This variant is advantageous when it is necessary toproduce a 1 number of devices 1 according to the invention; in fact, inthis case, it is possible to produce a custom microprocessor componenthaving hardware resources suitable for direct connection to the imagedetector 2.

[0051]FIG. 4 shows a device 1 a formed only by the image detector 2,wherein output 7 a of A/D converter 7 is connected to a data transferand control interface 35. Data transfer and control interface 35 is alsoconnected to the control unit 10 via a line 36 and to a personalcomputer (not shown) via a line 37. The data transfer and controlinterface 35 can for example be a USB, IEEE 1394 or SCSI interface; asan alternative a RAM interface can be provided, which allows thepersonal computer to collect directly the digital data supplied by theA/D conversion unit 7, or a DMAC interface. In addition, the datatransfer and control interface 35 can also be a radio interface, atelephone interface, or a GSM or satellite interface

[0052] Image detector 2 and data transfer and control interface 35 areadvantageously integrated in a single chip 38. In the illustratedexample, device 1 a of FIG. 4 is supplied directly by the personalcomputer, via a supply interface 39 connected to the personal computer(not shown) and supplying the necessary voltage to all blocks of FIG. 4.As an alternative, device 1 a can be supplied via data transfer andcontrol interface 35, or directly via the battery interface and thus beprovided with a supply unit block similar to block 80 of FIG. 2 (in amanner not shown).

[0053] The device 1 a of FIG. 4 can also be provided with input andoutput interfaces, similarly to interfaces 81 and 82 of FIG. 2.

[0054] Data transfer and control interface 35 transfers the imagesacquired to the personal computer and receives the commands from thelatter, so as to allow image processing (for example in the mannerdescribed in greater detail hereinafter with reference to FIG. 7) by thepersonal computer. This solution is advantageous when there is already apersonal. computer available for further processing (for examplestatistics, (computation etc), which can conveniently also be requiredto carry out the task of image processing, thus simplifying and reducingdimensions and cost of the device 1 a simply those of image detector 2and optionally transfer interface 35.

[0055]FIG. 5 shows a device 1 which has the same elements as the deviceof FIG. 1 (and which are therefore indicated with the same referencenumbers) and also an addition memory 25 of volatile type (RAM) connectedbetween A/D converter 7 and microprocessor 15. In detail, the additionalmemory 25 is connected to output 7 a of A/D converter 7 via a line 0.26,to microprocessor 15 via a data and address bus 27 and to logic controlunit 10 via a line 28.

[0056] The additional memory 25 is part of the image detector 2 andstores the digital image formed by a plurality of dots, the digitalvalue whereof is supplied by A/D converter 7. Thereby, a dedicatedcomponent outside image detector 2 is not necessary for image storing.

[0057] In the device 1 of FIG. 5, microprocessor 15 can accessadditional memory 25 directly via data bus 27, when it is necessary toaccess the image, and it can access its own RON memory 16 and R memory17, when executing the program or acceding to its own private data otherthan the image.

[0058] In addition, device 1 can be fully integrated (in a manner notshown) in a single chip with data and control transfer interface 35, orit can be only partially integrated, as previously described.

[0059]FIG. 6 shows a device 1 having the same elements as the device ofFIG. 1 and in addition a DMA (Direct Memory Access) controller 30,connected between A/D converter 7 and microprocessor 15. In detail, DMAcontroller 30 is connected to output 7 a of A/D converter 7 via a line31, to microprocessor 15 via a control line 32, to the samemicroprocessor 15, to ROM memory 3.6 and RAM memory 17 via a data bus 33and to logic control unit 10 via a line 34.

[0060] DMA controller 30 is part of the image detector 2 and has the aimof quickly furnishing available digital image to microprocessor 15, bytransferring it directly to RAM memory 17. In particular, when the imagemust be transferred to RAM

[0061] memory 17, the DMA controller 30 requests the microprocessor 15for control of the data bus 33, via the control line 32 and when itobtains this control, it generates the addresses and the control signalsnecessary to store the output image of A/D converter 7 directly in RAMmemory 17. When the transfer has been-carried out, control of data bus33 is returned to the microprocessor 1, which processes the image whichhas just been loaded.

[0062] The device 1 of FIG. 6 can also be integrated fully in a singlechip, or in only part of it.

[0063]FIG. 7 shows a device 1, having the same elements as the device ofFIG. 1. and also an additional RAM memory 25 a, similar to that of FIG.5, and a DMA controller 30 a, similar to that of FIG. 6. DMA controller30 a is connected in the same manner as that previously described withreference to FIG. 6 and the additional memory 25 a is connected at itsoutput directly to the data bus 33.

[0064] The device of 1 of FIG. 7 has the advantages of both thearchitecture of FIG. 5 and the architecture of FIG. 6. In fact, in thiscase, it is possible to create quickly a copy of the image contained inadditional memory 25 a into RAM. memory 17 and to acquire a secondimage, thus making it possible to carry out comparisons between twosuccessive images. This is very useful in the case of processing movingimages and in general whenever algorithms are used to process imagesbased on the comparison of two successive images.

[0065]FIG. 8 shows the more detailed architecture of a device 1, whichhas the general diagram shown in FIG. 1. In FIG. 8, CMOS. sensor 5 is oflinear type; analog processing unit 6 comprises a channel filter and anautomatic gain control unit; and A/D converter 7 is of the 1-bit type(digitizer). In detail, the analog processing unit 6 has the task ofselecting the useful band of the acquired signal, by filtering noisesuperimposed on the useful signal and automatically controlling theamplitude of the output signal supplied to A/D converter 7, thusadapting the gain to various operative conditions of contrast andintensity of the image acquired. Since A/D converter 7 operates with 1bit, conversion is particularly simple and quick. Image detector 2 isintegrated in a single chip and is connected to the external processingunit 3 formed by a microcontroller, including the microprocessor 15 andthe corresponding ROM memory 16 and RAM memory 17.

[0066]FIG. 9 shows more detailed architecture of another device 1, whichhas the general diagram shown in FIG. 1. In FIG. 9, CMOS sensor 5 is ofmatrix type; analog processing unit 6 comprises an analog circuit forsignal amplification and A/D converter 7 is of 8-bit type, so that itsupplies at output 7 a a digital signal encoding each pixel according toone of 256 levels of grey. Image detector 2 is integrated in a singlechip; microprocessor 15 is external, of RISC or CISC type, and isprovided with a non-volatile memory 16 (consisting in this case of anexternal EPROM) and of a RAM memory 17.—

[0067] The 8-bit A/D conversion limits the image transfer and processingcomplexity and speeds—up the image processing operations for acquiringdata contained in the image.

[0068] According to another embodiment shown in FIG. 10, a single chipintegrates a CMOS sensor 5 of linear type; an analog processing unit 6;an 8-bit A/D converter 7; a microprocessor' 15 and a RAM memory 17 forprogram data. In this solution; only ROM memory 16 is external.

[0069] In the device of FIG. 10, if the brightness level is known apriori (as in the case of contact readers), this is sufficient and thusthe level of the signal supplied by CMOS sensor 5 is sufficient, analogprocessing unit 6 is omitted.

[0070] The 8-bit converter ensures that the signal is converted withhigher resolution than in the case of FIG. 8. This solution thus makesit possible to simplify as far as possible, or even to eliminate analogprocessing of the signal and to implement algorithms for processing theimages in more complex digital formats. Through these algorithms it ispossible in particular to improve the reading performance, in case ofcodes with very low contrast, damaged codes etc.

[0071] To improve the reading speed, the device 1 functions as shown inthe flowchart of FIG. 11. In particular, initially in which there isdirect access to the pixels of the image detector 2, with. reference tothe flowchart of FIG. 11. It is assumed that a CMOS sensor 5 is used,wherein all pixels are the same and may be accessed directly byselecting lines 5 and columns which need not be adjacent, or byselecting rectangular windows of adjacent pixels, wherein the term“window” means a rectangular portion of the image with maximumresolution.

[0072] In this hypothesis, low-resolution acquisition 40 is carried outby a regular sub-sampling of the image with maximum resolution (thusobtaining for example a first image formed from one line out of everytwo and one column out of every two, of the image with maximumresolution).

[0073] The step of image analysis 43. is carried out by using analgorithm for identifying interest regions on the first image (reduceddimensions) obtained in step 40. This algorithm can for example searchfor the regions with greatest contrast and ignore the regions with lowcontrast, since the conventional optical codes use the alternation oflight and dark regions to encode data. Thereby, a list of interestregions is obtained.

[0074] The step of high-resolution acquisition 42 then comprisesacquiring, for each interest region, only the window containing theinterest region, at the maximum resolution. The decoding step 43 thenapplies the decoding algorithm to each portion of thus obtained image.

[0075] A different acquisition method is now described, using variableshape pixels. In particular, it is assumed that a CMOS sensor 5 is used,wherein all pixels are the same and adjacent pixels can be groupedtogether by hardware so as to be physically connected to one anotherthrough controllable switches in order to obtain macropixels withlarger. dimensions. In this respect, see FIGS. 12a and 12 b relative toa portion 50 of a CMOS sensor 5, formed from a plurality of elementarysensors 51, each of which supplies a corresponding pixel; in FIG. 12a,the elementary sensors 51, are distinct, whereas in FIG. 12b theelementary sensors 51 are grouped together such as to providemacropixels 52, formed by 2×2 pixels. The macropixels 52 are then usedand managed as single units, associated with a brightness valuecorrelated to the average of the brightness of the elementary 10 pixels.Thereby, images are generated having lower resolution than the maximum,that is when each individual elementary pixel 5 is independently used.

[0076] According to the variable-shape pixel method and with referenceto FIG. 11, the low-resolution acquisition step 40 comprises a first:step, wherein adjacent pixels are grouped together by hardware, on thebasis of control signals generated by control unit 10, in turncontrolled by the microprocessor 15, and a second step of acquiring alow resolution image, through the thus obtained macropixels. Thenfollow: analysis of image 41; high-resolution acquisition 42 (whereinthe values of the individual pixels are acquired only, in the windowswhere interest regions have been localized) and decoding 43, similarlyto the above-described 25 procedure with reference to the direct-accessmethod.

[0077] According to another aspect of the present invention, pixels witha variable height are used. This approach is particularly advantageousto improve the reading capability in case of linear bar codes andstacked codes (i.e. obtained by superimposing a series of bar codes witha very low height). Specifically, this method is based either on thepossibility of producing macropixels with a rectangular shape and adifferent number of elementary pixels, or on the possibility ofconfiguring height and active area of the pixel of the CMOS sensors inthe manner described

[0078] Specifically, for reading linear bodes (conventional bar codes),use of sensors with rectangular pixels having vertical dimensions muchgreater than horizontal dimensions (considering as horizontal thedirection of the reading line), makes it possible to obtain a relativelybroad sensitive detection area with respect to the horizontal dimension;thereby giving greater sensitivity and a better signal to noise ratio,as is immediately apparent by comparing FIGS. 13a and 14 a, relative tothe reading of a single bar code, respectively with pixels 55 with ahigh height to width ratio (which in the example illustrated is fargreater than 10) and with pixels 56 with a height to width ratio whichis close to 1.

[0079] On the other hand, sensors with a reduced pixel height areadvantageous in reading optical codes having elements not in line withthe pixels (FIGS. 13b and 14 b), or in reading stacked codes (FIGS. 13cand 14 c).

[0080] In particular the configurability of the pixel shape in CMOSsensors can be obtained by reducing appropriately the sensing area ofeach pixel. In fact, as is known, each CMOS pixel is formed by aphotoelement generating at the output an electric current correlated tothe received light quantity and used to charge a storage capacitor. Thephotoelement has superimposed a gate element, whose biasing makes itpossible to isolate a portion of the facing sensing area, thusactivating only part of the photoelement sensing area. Therefore, with asensing area of rectangular shape, such as that shown in fig-tires 13 a(for example of 200×14 μm) and by appropriately biasing the gateelectrode of each pixel, it is possible to modify the shape of eachpixel; for example, it is possible to activate, only one end of eachsensing' area, thus obtaining pixels with a substantially square shape,as shown in FIGS. 14a-14 c, or portions with increasing height, untilthe maximum dimensions of FIGS. 13a-13 b.

[0081] The above-described possibility of varying the shape of thepixels allows a same detector device to have two (or more) differentoperative configurations and thus to employ a single data acquisitiondevice for different codes or in a priori unknown reading conditions(for example with unknown inclination of a bar code).

[0082] In this case, an algorithm maybe implemented, initiallyattempting reading with maximum height and reducing the height in caseof unsuccessful reading. Height reduction can be gradual, if CMOS sensor5 allows a discrete regulation of the pixel height to obtain a pluralityof different heights.

[0083] In this case, the data acquisition device with variable shapepixels can operate according to FIG. 15. In detail, the maximum pixelheight is initially set (block 60); the image (or at least a reduced,trial portion of it) is then acquired (block 61); the acquired image isprocessed to extract coded data, for example for localizing interestregions, or is pre-processed to evaluate whether the image is sufficientto extract data, block 62; it is verified whether reading has beensuccessful, block 63; if so, (YES, output from block 63), processing iscontinued (completion of image processing or use of the extracted data,block 64); if not (NO output from block 63), it is verified whether thepixels are already at minimum height (block 67). If so (YES output fromblock 67), an error signal is generated (block 68, to indicate thatreading is impossible); if not (NO output from block 67), the pixelheight is reduced, block 69, and the image is acquired another time,returning to block 61.

[0084] The advantages of the described device and method are as follows.Firstly, they allow integration in a single chip of both the sensor andat least part of the VLSI logic circuits, thus reducing the costs forthe components and packaging of the entire device; in addition, theyexploit the inherent s advantages of CMOS technology for reading opticalcoded data; in particular, they allow acquisition of selective imagesub-sets, on the basis of the image processing stage thus simplifyingand speeding up data processing.

[0085] The present device can be produced according to one of thevarious above-described architectures, according to the specificapplication requirements and specific characteristics.

[0086] The possibility of integrating significant portions of the devicein a single chip permits firstly reduction of the device dimensions(which is particularly advantageous in case of manual optical readers,physically supported by an operator) and secondly, reduction of theprocessing times and interferences caused by connections, wires etc.

[0087] Finally, it is apparent that many modifications and variants canbe made to the device and the method described and illustrated here, allof which come within the context of the invention, as defined in theattached claims. In particular, the various blocks described withreference to specific architectures can also be used in differentarchitectures, in accordance with very varied combinations, on the basisof the specific requirements.

What is claimed is:
 1. A device for the acquisition and processing ofdata obtained from reading at least one type of optical code,comprising: means for generating an electric signal correlated to thebrightness of an image obtained through a CMOS optical sensor comprisinga plurality of pixels; and means, connected to said means for generatingsaid electrical signal, for processing said electric signal; whereinsaid means for generating said electric signal comprises acquisitionmeans for acquiring electric signals from said CMOS sensor according toat least one configuration of at least one member selected from thegroup consisting of shape and dimension of each pixel of at least aportion of said plurality of pixels, said configuration being dependenton said type of optical code.
 2. A device according to claim 1, whereinsaid CMOS optical sensor comprises a plurality of elementary pixels andsaid acquisition means comprises means for grouping elementary pixelstogether into pixels such that each of said pixels comprises at leastone elementary pixel, and further comprising means for acquiringelectric signals generated by said pixels.
 3. A device according toclaim 1, wherein said pixels have an active area and said acquisitionmeans comprises means for modifying the active area of said pixels, andfurther comprising means for acquiring electric signals supplied by saidpixels with a modified active area.
 4. A device according to claim 2,wherein said at least one configuration comprises a first configurationin which each of said pixels has at least a first dimension, and atleast a second configuration in which each of said pixels has at least asecond dimension different from the first dimension.
 5. A deviceaccording to claim 3, wherein said at least one configuration comprisesa first configuration in which each of said pixels has at least a firstdimension, and at least a second configuration in which each of saidpixels has at least a second dimension different from the firstdimension.
 6. A device for the acquisition and processing of dataobtained from reading at least one optical code, comprising: means forgenerating an electric signal correlated to the brightness of an imageobtained through a CMOS optical sensor comprising a plurality of pixels;and means for processing said electric signal, said processing meansbeing connected to said generating means; wherein said means forgenerating said electric signal comprises a acquisition means foracquiring electric signals from said CMOS optical sensor according to atleast one configuration of at least one member selected from the groupconsisting of shape and dimension of each pixel of at least a portion ofsaid plurality of pixels, said configuration being dependent on areading condition.
 7. A device for the acquisition and processing ofdata obtained from reading at least one optical code, comprising: meansfor generating an electric signal correlated to the brightness of animage obtained through a CMOS optical sensor; and means for processingsaid electric signal, said processing means being connected to saidgenerating means; wherein said means for generating said electric signalcomprises a configuration means for acquiring electric signals from saidCMOS optical sensor and according to at least one configuration that isdependent on a reading condition; and wherein said CMOS optical sensorcomprises a plurality of sensing elements and said configuration meanscomprises means for grouping elements of said sensing elements togetherinto a corresponding number of macropixels such that each of saidmacropixels comprises at least one sensing element, and furthercomprising means for acquiring electric signals generated by saidmacropixels.
 8. A device for the acquisition and processing of dataobtained from reading at least one optical code, comprising: means forgenerating an electric signal correlated to the brightness of an imageobtained through a CMOS optical sensor; and means for processing saidelectric signal, said processing means being connected to saidgenerating means; wherein said means for generating said electric signalcomprises a configuration means for acquiring electric signals from saidCMOS optical sensor and according to at least one configuration that isdependent on a reading condition, wherein said CMOS optical sensorcomprises a plurality of sensing elements having an active area, andsaid configuration means further comprises means for modifying theactive area of said sensing elements; and said device further comprisingmeans for acquiring electric signals supplied by said sensing elementswith a modified active area.
 9. A device according to claim 7, whereinsaid at least one configuration comprises a first configuration in whicheach of said macropixels has at least a first dimension, and at leastone second configuration in which each of said macropixes has at leastone second dimension that is different from the first dimension.
 10. Adevice according to claim 8, wherein said at least one configurationcomprises a first configuration in which each of said sensing elementshas at least one first dimension, and at least one second configurationin which each of said sensing element has at least one second dimensionthat is different from the first dimension.
 11. A device for theacquisition and processing of data obtained from reading optical codes,comprising: means for generating an electric signal correlated to thebrightness of an image obtained through a CMOS optical sensor; and meansfor processing said electric signal; wherein said processing means isconnected to said generating means; wherein said means for generatingsaid electric signal comprises configuration means for acquiringelectric signals from said CMOS sensor according to a firstconfiguration when acquiring a linear bar code, and according to atleast one second configuration different from the first configurationwhen acquiring a stacked code.
 12. A device according to claim 11,wherein said CMOS optical sensor comprises a plurality of elementarypixels and said configuration means comprises means for grouping saidelementary pixels together into pixels such that each of said pixelscomprises at least one elementary pixel, and further comprising meansfor acquiring electric signals generated by said pixels.
 13. A deviceaccording to claim 11, wherein said CMOS optical sensor furthercomprises a plurality of sensing elements having an active area and saidconfiguration means comprises means for modifying said active area ofsaid sensing elements; and means for acquiring electric signals suppliedby said sensing elements with a modified active area.
 14. A deviceaccording to claim 11, wherein said CMOS optical sensor comprises aplurality of pixels and, when said configuration means acquires saidelectric signals according to said first configuration, said pixels haveat least a first dimension and, when said configuration means acquiressaid electric signals according to said at least one secondconfiguration, said pixels have at least a second dimension differentfrom said first dimension.
 15. A method for the acquisition andprocessing of data obtained from reading at least one optical code,comprising the steps of: a) generating an electric signal correlated tothe brightness of an image obtained through a CMOS optical sensorcomprising a plurality of pixels; b) processing said electric signal;wherein step a) comprises a step c) of acquiring electric signals fromsaid CMOS sensor according to at least one configuration of at least onemember selected from the group consisting of shape and dimension of eachpixel of at least a portion of said plurality of pixels, saidconfiguration being dependent on the type of optical code.
 16. A methodfor the acquisition and processing of data_obtained from reading atleast one optical code, comprising the steps of: a) generating anelectric signal correlated to the brightness of an image obtainedthrough a CMOS optical sensor; b) processing said electric signal;wherein step a) comprises a step c) of acquiring electric signals fromsaid CMOS sensor according to at least one configuration dependent onthe type of optical code, wherein said CMOS optical sensor comprises aplurality of elementary pixels, and wherein step c) comprises the stepsof: grouping elementary pixels together into pixels such that each ofsaid pixels comprises at least one elementary pixel; and acquiringelectric signals generated by said pixels.
 17. A method for theacquisition and processing of data obtained from reading at least oneoptical code, comprising the steps of: a) generating an electric signalcorrelated to the brightness of an image obtained through a CMOS opticalsensor; b) processing said electric signal; wherein step a) comprises astep c) of acquiring electric signals from said CMOS sensor according toat least one configuration dependent on the type of optical code whereinsaid CMOS optical sensor comprises a plurality of sensing elementshaving an active area and step c) comprises the steps of: modifying theactive area of said sensing elements; and acquiring electric signalssupplied by said sensing elements with a modified active area.
 18. Amethod according to claim 15, wherein said step c) further comprises thestep of modifying the shape of said pixels.
 19. A method according toclaim 15, wherein said step c) further comprises the step of modifyingat least one dimension of said pixels.
 20. A method for the acquisitionand processing of data obtained from reading at least one optical code,comprising the steps of: a) generating an electric signal correlated tothe brightness of an image obtained through a CMOS optical sensorcomprising a plurality of pixels; and b) processing said electricsignal; wherein step a) comprises a step c) of acquiring electricsignals from said CMOS sensor according to at least one configuration ofat least one member selected from the group consisting of shape anddimension of each pixel of at least a portion of said plurality ofpixels, said configuration being dependent on a reading condition.
 21. Amethod for the acquisition and processing of data obtained from readingat least one optical code, comprising the steps of: a) generating anelectric signal correlated to the brightness of an image obtainedthrough a CMOS optical sensor; and b) processing said electric signal;wherein step a) comprises a step c) of acquiring electric signals fromsaid CMOS sensor according to at least one configuration that isdependent on a reading condition, wherein said CMOS optical sensorcomprises a plurality of elementary pixels, and wherein said step c)comprises the step of grouping elementary pixels together into pixelssuch that each of said pixels comprises at least one elementary pixel;and said method further comprising the step of acquiring electricsignals generated by said pixels.
 22. A method for the acquisition andprocessing of data obtained from reading at least one optical code,comprising the steps of: a) generating an electric signal correlated tothe brightness of an image obtained through a CMOS optical sensor; andb) processing said electric signal; wherein step a) comprises a step c)of acquiring electric signals from said CMOS sensor according to atleast one configuration that is dependent on a reading condition,wherein said CMOS optical sensor comprises a plurality of sensingelements having an active area and wherein said step c) comprises thesteps of: modifying the active area of said sensing elements; andacquiring electric signals supplied by said sensing elements with amodified active area.
 23. A method according to claim 20, wherein saidstep c) further comprises modifying the shape of said pixels.
 24. Amethod according to claim 20, wherein said step c) further comprises thestep of modifying at least one dimension of said pixels.
 25. A methodfor the acquisition and processing of data obtained from reading opticalcodes, comprising the steps of: a) acquiring an image through a CMOSoptical sensor comprising a plurality of pixels; b) processing saidimage to extract optical coded data there from; c) attempting a readingof said extracted optical coded data; d) verifying whether the readingof said step c) has been successful; e) if the verification of said stepd) has not been successful, modifying the shape of said pixels andreturning to step a).
 26. A method according to claim 25, wherein saidstep a) is preceded by a step i) of setting a height for said pixels;and wherein the modification of said step e) comprises the step ofreducing said pixel height.
 27. A method according to claim 25, whereinat least one of said pixels comprises at least one elementary pixel, andstep e) comprises varying the number of elementary pixels of said pixel.28. A method according to claim 25, wherein at least one of said pixelshas an active area, and said step e) comprises modifying the active areaof said pixel.
 29. A device for the acquisition and processing of dataobtained from optical codes, comprising: means for generating anelectric signal correlated to the brightness of an image through a CMOSoptical sensor comprising a plurality of pixels; and means, connected tosaid means for generating said electric signal, for processing saidelectric signal; wherein said means for generating said electric signalcomprises acquisition means for acquiring electric signals from saidCMOS sensor according to a first pixel configuration for a first type ofoptical code and according to at least a second pixel configuration forat least one different type of optical code, said first and secondconfigurations being different from each other at least in one of shapeand dimension of the respective pixels.
 30. A device according to claim29, wherein, in said first configuration, each of said respective pixelshas at least a first dimension and wherein, in said at least one secondconfiguration, each of said respective pixels has at least acorresponding second dimension different from the first dimension.
 31. Adevice according to claim 29, wherein, in said first configuration, eachof said respective pixels has a first shape and in said at least onesecond configuration each of said respective pixels has second shapedifferent from the first shape.
 32. A device according to claim 29,wherein said CMOS optical sensor comprises a plurality of elementarypixels and said acquisition means comprises means for groupingelementary pixels together into said pixels such that each of saidpixels comprises at least one elementary pixel and wherein, in saidfirst configuration, each of said respective pixels comprises a firstnumber of elementary pixels and, in said at least one secondconfiguration, each of said respective pixels comprises a second numberof elementary pixels different from the first one.
 33. A method for theacquisition and processing of data obtained from reading optical codes,comprising the steps of: a) acquiring a first image through a CMOSoptical sensor comprising a plurality of pixels, said first image beingacquired by acquisition of electric signals from said CMOS sensoraccording to a first configuration of at least a portion of saidplurality of pixels; b) processing said image to extract optical codeddata there from; c) attempting a reading of said extracted optical codeddata; d) verifying whether the reading of said step c) has beensuccessful; e) if the verification of said step d) has a negativeresult, acquiring a second image by acquisition of electric signals fromsaid CMOS sensor according to a second configuration different from saidfirst configuration at least in one of shape and dimension of therespective pixels.
 34. A device for the automatic acquisition of dataobtained from optical codes, said device being connectable to anexternal data-processing unit, said device comprising: a CMOS opticalsensor, comprising a plurality of CMOS sensing elements, adapted togenerate an analog electric signal correlated to the light incident onsaid CMOS sensing elements; an analog processing unit connected to saidCMOS optical sensor adapted to process said analog electric signal; andan analog/digital conversion unit connected to said analog processingunit adapted to convert said analog electric signal into a digitalsignal; wherein said device further comprises: a transfer interface unitconnected to said analog/digital conversion unit adapted to directlytransfer said digital signal to said external data-processing unit. 35.A device according to claim 34, wherein said transfer interface unit isat least one member selected from the group consisting of: a USBinterface, a radio interface, a telephone interface, a GSM interface anda satellite interface.
 36. A device according to claim 34, wherein saidtransfer interface unit is a RAM.
 37. A device according to claim 34,wherein said transfer interface unit is a Direct Memory AccessController.
 38. A device according to claim 34, wherein said transferinterface unit is further adapted to receive commands from said externaldata-processing unit.
 39. A device according to claim 34, wherein saidCMOS optical sensor and at least one element, selected from the groupconsisting of said analog processing unit, said analog/digitalconversion unit and said transfer interface unit are integrated in asingle chip.
 40. A method for automatically acquiring data obtained fromoptical codes by means of an acquisition device, the method comprisingthe steps of: generating an analog electric signal correlated to thebrightness of an image through a CMOS optical sensor; analog processingsaid analog electric signal; and converting said analog electric signalinto a digital signal; said method further comprising the step ofsending said digital signal to a transfer interface unit, included insaid acquisition device, for the direct transfer of said digital signalto a data-processing unit external to said acquisition device.
 41. Adevice for the acquisition and automatic processing of data obtainedfrom optical codes, comprising: a CMOS optical sensor, comprising aplurality of CMOS sensing elements, adapted to generate an analogelectric signal correlated to the light incident on said CMOS sensingelements; an analog processing unit connected to said CMOS opticalsensor adapted to process said analog electric signal; an analog/digitalconversion unit connected to said analog processing unit adapted toconvert said analog electric signal into a digital signal; and adata-processing unit, connected to said analog/digital conversion unit,adapted to process said digital signal to extract coded optical data,wherein said device further comprises: an unit functionally interposedbetween said analog/digital conversion unit and said data-processingunit for rendering said digital signal accessible to saiddata-processing unit.
 42. A device according to claim 41, wherein saiddata-processing unit comprises at least one member selected from thegroup consisting of: a microprocessor; a program memory unit; and animage memory unit.
 43. A device according to claim 42, wherein said unitcomprises a Direct Memory Access Controller functionally interposedbetween said analog/digital conversion unit and said image memory unit.44. A device according to claim 41, wherein said interface unitcomprises storing means functionally interposed between saidanalog/digital conversion unit and said data processing unit.
 45. Adevice according to claim 44, wherein said storing means is a volatilememory.
 46. A device according to claim 41, further comprising a logiccontrol unit connected to said CMOS optical sensor, to said analogprocessing unit, to said analog/digital conversion unit and to said dataprocessing unit.
 47. A device according to claim 46, wherein saiddata-processing unit comprises a micro-processor and said logic controlunit is integrated in said microprocessor.
 48. A device according toclaim 46, wherein said logic control unit is distributed in said CMOSsensor, said analog processing unit and said analog/digital conversionunit.
 49. A device according to claim 46, wherein said CMOS opticalsensor and at least one element, selected from the group consisting ofsaid analog processing unit, said analog/digital conversion unit andsaid logic control unit, are integrated in a single image detector. 50.A device according to claim 41, further comprising a battery supplyunit.
 51. A device according to claim 41, further comprising userinterface means.
 52. A device according to claim 51, wherein said userinterface means comprise a display unit.
 53. A device according to claim51, wherein said user interface means comprises at least one memberselected from a keyboard and a mouse.
 54. A device according to claim41, further comprising means for acquiring low-resolution images; meansfor searching regions of interest in said low-resolution images; meansfor acquiring high-resolution images for said regions of interest andmeans for decoding data in said high-resolution images.
 55. A deviceaccording to claim 54, wherein said low-resolution image acquisitionmeans comprise means for selectively interrogating only some of saidCMOS sensing elements of said plurality of CMOS sensing elements.
 56. Adevice according to claim 54, wherein said low-resolution imageacquisition means comprises means for grouping adjacent groups of saidCMOS sensing elements together into macropixels and means for acquiringelectric signals generated by each of said macropixels.
 57. A deviceaccording to claim 54, wherein said low-resolution image acquisitionmeans comprise means for modifying the active area of said CMOS sensingelements and means for acquiring electric signals supplied by said CMOSsensing elements with a modified active area.